Bob La Londe wrote:
"Ignoramus11933" wrote in message
...
As I was messing around with text engraving, I realized that it would
be very cool to have a high speed spindle.
There is, apparently, a wide variety of purpose made and adapted
devices that are used for this:
http://www.cnccookbook.com/CCHighSpeedSpindleAddOn.htm
The best so far, looks to be this:
http://www.cnccookbook.com/img/Other...Manifold_1.jpg
This is a Bosch Colt palm router attached to the quill. It seems to be
nicely made, and low profile.
In my case, I can use a changeable toolholder to do the attaching, so
that it is easy to take off:
http://www.shars.com/products/view/1...nd_Mill_Holder
This way, I could run a 1/8" end mill at 30,000 RPM, without using the
main mill's spindle bearings. I would use a brake to hold this
assembly in the quill.
It would be, as I said, a quick change setup, easy to be swapped
out. I would just need to figure out a safety interlock mechanism, so
that the main spindle would not be turned on accidentally with this
thing mounted.
It would seem that a holder is easy to make from 6061 or some such,
and the whole project can be done under $200.
I engraved some text yesterday, which took something like 19
minutes. I did it at 2,400 RPM. At 30,000 RPM, it could take only 1.5-2
minutes.
I guess it depends on what you mean by engraving. Engraving is usually done
with a spring loaded bit holder that is dragged (not spinning) along the
surface of the material.
Actually, most engraving *is* done with a rotating bit, usually fixed,
but sometimes in a spring loaded mount. All the plastic signs and
nameplates you see are engraved with a rotary bit. Most engraving on
stuff like anodized AL is also rotary cut (or lasered). Drag engraving
is the exception, not the norm.
Iggy will find a high speed spindle and a nice carbide rotary engraving
bit work nicely to engrave lettering and markings on aluminum or plastic
enclosures which can be paint filled for a very nice result.